Blue luminescent complexes based on 5-aminodiacetic isophthalic ligand

The reactions of Cd(CH3COO)2·2H2O or Zn(CH3COO)2·2H2O and 5-aminodiacetic isophthalic acid (H4adip) with 1,10′-phenanthroline (phen) ligand gave rise to two blue luminescent coordination mononuclear complexes: [Cd(phen)(H3adip)2(H2O)2]·0.5H2O (1) and Zn(phen)(H3adip)2 (2), respectively. 1 crystallizes in the triclinic space group P-1, with a=6.2889(2), b=16.1556(5), c=18.4277(7) Å, α=97.722(12), β=94.338(9), γ=95.039(7)°, V=1840.86(11) Å3, Z=2. Complex 2 crystallizes in monoclinic, space group C2/c with a=22.639(8), b=9.813(3), c=15.708(6) Å, β=110.928(4)°, V=3259(2) Å3, Z=4. Carboxylic groups in both structures are involved in strong hydrogen bonding interactions. At room temperature, complex 1 exhibits an intense emission at 474 nm upon 380 nm excitation, while complex 2 exhibits an intense emission at 485 nm upon 365 nm excitation, which are contributed from ligand-to-metal charge-transfer (LMCT).